On 4/2/25 15:47, Thomas Zimmermann wrote: > Hi > > Am 22.03.25 um 22:26 schrieb Dmitry Osipenko: >> The vmapped pages shall be pinned in memory and previously get/ >> put_pages() >> were implicitly hard-pinning/unpinning the pages. This will no longer be >> the case with addition of memory shrinker because pages_use_count > 0 >> won't >> determine anymore whether pages are hard-pinned (they will be soft- >> pinned), >> while the new pages_pin_count will do the hard-pinning. Switch the >> vmap/vunmap() to use pin/unpin() functions in a preparation of addition >> of the memory shrinker support to drm-shmem. > > I've meanwhile rediscovered this patch and I'm sure this is not correct. > Vmap should not pin AFAIK. It is possible to vmap if the buffer has been > pinned, but that's not automatic. For other vmaps it is necessary to > hold the reservation lock to prevent the buffer from moving.
Hi, with vmap() you're getting a kernel address. The GEM's memory should be not movable while it's vmapped as we can't handle kernel page faults. Not sure what you're meaning by the "other vmaps", please clarify. -- Best regards, Dmitry
